Astronomers have for the first time detected stars that are blasting radio signals hinting at the presence of hidden planets around them, as shown in a major discovery recently. The signals were picked up using the Low-Frequency Array (LOFAR) situated in the Netherlands, which is considered the world’s most powerful radio antenna.
The new technique of spotting hidden planets could hint at the possibility of life in the system. The signals were detected by Dr Benjamin Pope from the University of Queensland and his colleagues at the Dutch national observatory ASTRON. The astronomers have been searching for planets using LOFAR.
The astronomers have detected signals from 19 distant red dwarfs. Four of the 19 distant red dwarfs are best explained by the existence of planets orbiting them. The astronomers in a statement said, “We’ve long known that the planets of our own solar system emit powerful radio waves as their magnetic fields interact with the solar wind, but radio signals from planets outside our solar system had yet to be picked up.”
Earlier, astronomers were only able to detect the very nearest stars in steady radio emission. Everything else in the radio sky was interstellar gas or black holes. Meanwhile, Radio astronomers are now able to see plain old stars when they make their observations as the team focused on red dwarf stars. These stars are much smaller than the Sun and known to have an intense magnetic activity that drives stellar flares and radio emission.
In a study published in Nature Astronomy, the team is confident these signals are coming from the magnetic connection of the stars and unseen orbiting planets, similar to the interaction between Jupiter and its moon. Dr Joseph Callingham at Leiden University, ASTRON and lead author of the discovery said, “Our own Earth has auroras, commonly recognised here as the northern and southern lights, that also emit powerful radio waves this is from the interaction of the planet’s magnetic field with the solar wind.”
Meanwhile, researchers designed a model to study the interaction of the magnetic field with the solar wind just as it happens between Jupiter and its Moon Io that drives auroras on the largest planet in the solar system. These auroras are much stronger than the ones we see on Earth. They then scaled up the model to detect radio emissions from distant stars.